summaryrefslogtreecommitdiff
path: root/src/hashmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/hashmap.c')
-rw-r--r--src/hashmap.c543
1 files changed, 543 insertions, 0 deletions
diff --git a/src/hashmap.c b/src/hashmap.c
new file mode 100644
index 0000000000..5a993b6e47
--- /dev/null
+++ b/src/hashmap.c
@@ -0,0 +1,543 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "util.h"
+#include "hashmap.h"
+#include "macro.h"
+
+#define NBUCKETS 127
+
+struct hashmap_entry {
+ const void *key;
+ void *value;
+ struct hashmap_entry *bucket_next, *bucket_previous;
+ struct hashmap_entry *iterate_next, *iterate_previous;
+};
+
+struct Hashmap {
+ hash_func_t hash_func;
+ compare_func_t compare_func;
+
+ struct hashmap_entry *iterate_list_head, *iterate_list_tail;
+ unsigned n_entries;
+};
+
+#define BY_HASH(h) ((struct hashmap_entry**) ((uint8_t*) (h) + ALIGN(sizeof(Hashmap))))
+
+unsigned string_hash_func(const void *p) {
+ unsigned hash = 0;
+ const char *c;
+
+ for (c = p; *c; c++)
+ hash = 31 * hash + (unsigned) *c;
+
+ return hash;
+}
+
+int string_compare_func(const void *a, const void *b) {
+ return strcmp(a, b);
+}
+
+unsigned trivial_hash_func(const void *p) {
+ return PTR_TO_UINT(p);
+}
+
+int trivial_compare_func(const void *a, const void *b) {
+ return a < b ? -1 : (a > b ? 1 : 0);
+}
+
+Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func) {
+ Hashmap *h;
+
+ if (!(h = malloc0(ALIGN(sizeof(Hashmap)) + NBUCKETS * ALIGN(sizeof(struct hashmap_entry*)))))
+ return NULL;
+
+ h->hash_func = hash_func ? hash_func : trivial_hash_func;
+ h->compare_func = compare_func ? compare_func : trivial_compare_func;
+
+ h->n_entries = 0;
+ h->iterate_list_head = h->iterate_list_tail = NULL;
+
+ return h;
+}
+
+int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t compare_func) {
+ assert(h);
+
+ if (*h)
+ return 0;
+
+ if (!(*h = hashmap_new(hash_func, compare_func)))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void link_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) {
+ assert(h);
+ assert(e);
+
+ /* Insert into hash table */
+ e->bucket_next = BY_HASH(h)[hash];
+ e->bucket_previous = NULL;
+ if (BY_HASH(h)[hash])
+ BY_HASH(h)[hash]->bucket_previous = e;
+ BY_HASH(h)[hash] = e;
+
+ /* Insert into iteration list */
+ e->iterate_previous = h->iterate_list_tail;
+ e->iterate_next = NULL;
+ if (h->iterate_list_tail) {
+ assert(h->iterate_list_head);
+ h->iterate_list_tail->iterate_next = e;
+ } else {
+ assert(!h->iterate_list_head);
+ h->iterate_list_head = e;
+ }
+ h->iterate_list_tail = e;
+
+ h->n_entries++;
+ assert(h->n_entries >= 1);
+}
+
+static void unlink_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) {
+ assert(h);
+ assert(e);
+
+ /* Remove from iteration list */
+ if (e->iterate_next)
+ e->iterate_next->iterate_previous = e->iterate_previous;
+ else
+ h->iterate_list_tail = e->iterate_previous;
+
+ if (e->iterate_previous)
+ e->iterate_previous->iterate_next = e->iterate_next;
+ else
+ h->iterate_list_head = e->iterate_next;
+
+ /* Remove from hash table bucket list */
+ if (e->bucket_next)
+ e->bucket_next->bucket_previous = e->bucket_previous;
+
+ if (e->bucket_previous)
+ e->bucket_previous->bucket_next = e->bucket_next;
+ else
+ BY_HASH(h)[hash] = e->bucket_next;
+
+ assert(h->n_entries >= 1);
+ h->n_entries--;
+}
+
+static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
+ unsigned hash;
+
+ assert(h);
+ assert(e);
+
+ hash = h->hash_func(e->key) % NBUCKETS;
+
+ unlink_entry(h, e, hash);
+ free(e);
+}
+
+void hashmap_free(Hashmap*h) {
+
+ if (!h)
+ return;
+
+ hashmap_clear(h);
+
+ free(h);
+}
+
+void hashmap_clear(Hashmap *h) {
+ if (!h)
+ return;
+
+ while (h->iterate_list_head)
+ remove_entry(h, h->iterate_list_head);
+}
+
+static struct hashmap_entry *hash_scan(Hashmap *h, unsigned hash, const void *key) {
+ struct hashmap_entry *e;
+ assert(h);
+ assert(hash < NBUCKETS);
+
+ for (e = BY_HASH(h)[hash]; e; e = e->bucket_next)
+ if (h->compare_func(e->key, key) == 0)
+ return e;
+
+ return NULL;
+}
+
+int hashmap_put(Hashmap *h, const void *key, void *value) {
+ struct hashmap_entry *e;
+ unsigned hash;
+
+ assert(h);
+
+ hash = h->hash_func(key) % NBUCKETS;
+
+ if ((e = hash_scan(h, hash, key))) {
+
+ if (e->value == value)
+ return 0;
+
+ return -EEXIST;
+ }
+
+ if (!(e = new(struct hashmap_entry, 1)))
+ return -ENOMEM;
+
+ e->key = key;
+ e->value = value;
+
+ link_entry(h, e, hash);
+
+ return 1;
+}
+
+int hashmap_replace(Hashmap *h, const void *key, void *value) {
+ struct hashmap_entry *e;
+ unsigned hash;
+
+ assert(h);
+
+ hash = h->hash_func(key) % NBUCKETS;
+
+ if ((e = hash_scan(h, hash, key))) {
+ e->key = key;
+ e->value = value;
+ return 0;
+ }
+
+ return hashmap_put(h, key, value);
+}
+
+void* hashmap_get(Hashmap *h, const void *key) {
+ unsigned hash;
+ struct hashmap_entry *e;
+
+ if (!h)
+ return NULL;
+
+ hash = h->hash_func(key) % NBUCKETS;
+
+ if (!(e = hash_scan(h, hash, key)))
+ return NULL;
+
+ return e->value;
+}
+
+void* hashmap_remove(Hashmap *h, const void *key) {
+ struct hashmap_entry *e;
+ unsigned hash;
+ void *data;
+
+ if (!h)
+ return NULL;
+
+ hash = h->hash_func(key) % NBUCKETS;
+
+ if (!(e = hash_scan(h, hash, key)))
+ return NULL;
+
+ data = e->value;
+ remove_entry(h, e);
+
+ return data;
+}
+
+int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value) {
+ struct hashmap_entry *e;
+ unsigned old_hash, new_hash;
+
+ if (!h)
+ return -ENOENT;
+
+ old_hash = h->hash_func(old_key) % NBUCKETS;
+ if (!(e = hash_scan(h, old_hash, old_key)))
+ return -ENOENT;
+
+ new_hash = h->hash_func(new_key) % NBUCKETS;
+ if (hash_scan(h, new_hash, new_key))
+ return -EEXIST;
+
+ unlink_entry(h, e, old_hash);
+
+ e->key = new_key;
+ e->value = value;
+
+ link_entry(h, e, new_hash);
+
+ return 0;
+}
+
+void* hashmap_remove_value(Hashmap *h, const void *key, void *value) {
+ struct hashmap_entry *e;
+ unsigned hash;
+
+ if (!h)
+ return NULL;
+
+ hash = h->hash_func(key) % NBUCKETS;
+
+ if (!(e = hash_scan(h, hash, key)))
+ return NULL;
+
+ if (e->value != value)
+ return NULL;
+
+ remove_entry(h, e);
+
+ return value;
+}
+
+void *hashmap_iterate(Hashmap *h, Iterator *i, const void **key) {
+ struct hashmap_entry *e;
+
+ assert(i);
+
+ if (!h)
+ goto at_end;
+
+ if (*i == ITERATOR_LAST)
+ goto at_end;
+
+ if (*i == ITERATOR_FIRST && !h->iterate_list_head)
+ goto at_end;
+
+ e = *i == ITERATOR_FIRST ? h->iterate_list_head : (struct hashmap_entry*) *i;
+
+ if (e->iterate_next)
+ *i = (Iterator) e->iterate_next;
+ else
+ *i = ITERATOR_LAST;
+
+ if (key)
+ *key = e->key;
+
+ return e->value;
+
+at_end:
+ *i = ITERATOR_LAST;
+
+ if (key)
+ *key = NULL;
+
+ return NULL;
+}
+
+void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key) {
+ struct hashmap_entry *e;
+
+ assert(i);
+
+ if (!h)
+ goto at_beginning;
+
+ if (*i == ITERATOR_FIRST)
+ goto at_beginning;
+
+ if (*i == ITERATOR_LAST && !h->iterate_list_tail)
+ goto at_beginning;
+
+ e = *i == ITERATOR_LAST ? h->iterate_list_tail : (struct hashmap_entry*) *i;
+
+ if (e->iterate_previous)
+ *i = (Iterator) e->iterate_previous;
+ else
+ *i = ITERATOR_FIRST;
+
+ if (key)
+ *key = e->key;
+
+ return e->value;
+
+at_beginning:
+ *i = ITERATOR_FIRST;
+
+ if (key)
+ *key = NULL;
+
+ return NULL;
+}
+
+void *hashmap_iterate_skip(Hashmap *h, const void *key, Iterator *i) {
+ unsigned hash;
+ struct hashmap_entry *e;
+
+ if (!h)
+ return NULL;
+
+ hash = h->hash_func(key) % NBUCKETS;
+
+ if (!(e = hash_scan(h, hash, key)))
+ return NULL;
+
+ *i = (Iterator) e;
+
+ return e->value;
+}
+
+void* hashmap_first(Hashmap *h) {
+
+ if (!h)
+ return NULL;
+
+ if (!h->iterate_list_head)
+ return NULL;
+
+ return h->iterate_list_head->value;
+}
+
+void* hashmap_last(Hashmap *h) {
+
+ if (!h)
+ return NULL;
+
+ if (!h->iterate_list_tail)
+ return NULL;
+
+ return h->iterate_list_tail->value;
+}
+
+void* hashmap_steal_first(Hashmap *h) {
+ void *data;
+
+ if (!h)
+ return NULL;
+
+ if (!h->iterate_list_head)
+ return NULL;
+
+ data = h->iterate_list_head->value;
+ remove_entry(h, h->iterate_list_head);
+
+ return data;
+}
+
+unsigned hashmap_size(Hashmap *h) {
+
+ if (!h)
+ return 0;
+
+ return h->n_entries;
+}
+
+bool hashmap_isempty(Hashmap *h) {
+
+ if (!h)
+ return true;
+
+ return h->n_entries == 0;
+}
+
+int hashmap_merge(Hashmap *h, Hashmap *other) {
+ struct hashmap_entry *e;
+
+ assert(h);
+
+ if (!other)
+ return 0;
+
+ for (e = other->iterate_list_head; e; e = e->iterate_next) {
+ int r;
+
+ if ((r = hashmap_put(h, e->key, e->value)) < 0)
+ if (r != -EEXIST)
+ return r;
+ }
+
+ return 0;
+}
+
+void hashmap_move(Hashmap *h, Hashmap *other) {
+ struct hashmap_entry *e, *n;
+
+ assert(h);
+
+ /* The same as hashmap_merge(), but every new item from other
+ * is moved to h. This function is guaranteed to succeed. */
+
+ if (!other)
+ return;
+
+ for (e = other->iterate_list_head; e; e = n) {
+ unsigned h_hash, other_hash;
+
+ n = e->iterate_next;
+
+ h_hash = h->hash_func(e->key) % NBUCKETS;
+
+ if (hash_scan(h, h_hash, e->key))
+ continue;
+
+ other_hash = other->hash_func(e->key) % NBUCKETS;
+
+ unlink_entry(other, e, other_hash);
+ link_entry(h, e, h_hash);
+ }
+}
+
+int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key) {
+ unsigned h_hash, other_hash;
+ struct hashmap_entry *e;
+
+ if (!other)
+ return 0;
+
+ assert(h);
+
+ h_hash = h->hash_func(key) % NBUCKETS;
+ if (hash_scan(h, h_hash, key))
+ return -EEXIST;
+
+ other_hash = other->hash_func(key) % NBUCKETS;
+ if (!(e = hash_scan(other, other_hash, key)))
+ return -ENOENT;
+
+ unlink_entry(other, e, other_hash);
+ link_entry(h, e, h_hash);
+
+ return 0;
+}
+
+Hashmap *hashmap_copy(Hashmap *h) {
+ Hashmap *copy;
+
+ assert(h);
+
+ if (!(copy = hashmap_new(h->hash_func, h->compare_func)))
+ return NULL;
+
+ if (hashmap_merge(copy, h) < 0) {
+ hashmap_free(copy);
+ return NULL;
+ }
+
+ return copy;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-10 13:15:16 +0000